# rhedyn

a quick and dirty static site generator with intelligent caching.

Run this script from a directory containing markdown, templates and styles and a `dist/` directory will be created
containing the rendered-out static assets ready for deployment.

While the defaults should work for most (of my) use cases, you can configure behaviour using a `rhedyn.config.js` in the
directory where you run the tool.

"Rhedyn" is Welsh for "fern", and is pronounced a bit like "read in". 

## Installation and usage

The default config will look for `.md` files in the `markdown/` directory, `.scss` files in the `styles/` directory, and
handlebars (`.hbs`) files in the `templates/` directory. It also processes images, SVG icons, static files, and generates favicons.

The styles will be compiled using `sass` and output to a matching path in the `dist/` directory with a `.css` file
extension. These file paths are made available to the template renderer, for inclusion as whatever tags you see fit.

Markdown is compiled using `marked` with the `marked-code-preview` extension enabled, then passed to the template
renderer in the `content` property. Images referenced in markdown are automatically processed and converted to responsive
srcsets if matching images are found in the images task.

Once the markdown content and template have been rendered out, the resulting `.html` file is minified and output to `dist/`, 
with the matching path (e.g. `markdown/recipes/soup.md` would be rendered to `dist/recipes/soup.html`).

Usual stuff applies - install as a module locally or globally and call the default function:

`npx rhedyn`

```
"scripts": {
  "build": "rhedyn"
}
```

You can also build a self-contained executable if you like chunky binaries with `npm run build`. That'll output to the
`dist/` directory, and you can then put that binary wherever you like (probably somewhere in your $path).

## Caching

Rhedyn includes intelligent caching that tracks both file dependencies and configuration state. Tasks are only re-run when:
- Input files have changed (detected via file hashes)
- Configuration has changed (detected via state hashes)
- Output files are missing (can be skipped by setting `opts.ignoreExisting` to `true`)

Cache files are stored in `.cache/` by default and can be disabled by setting `cacheDir: false` in your config.

If output file checks are skipped with `ignoreExisting`, only files that have changed inputs will be output.

You can get additional detail on state cache misses by setting `opts.includeStateValues` to `true`, at the cost of
considerably larger cache files.

## Configuration

A working example of how to configure can be found in `src/defaults.js`, with the processors separated out to
`src/processors.js` for tidiness. 

Your `rhedyn.config.js` should export an object with "tasks" and "opts". These are detailed below.

If you want to extend the default config, it can be imported as `defaultConfig` from this package.

#### opts

The `opts` object in your config is for anything related to the project as a whole, rather than individual tasks. That
means things like the base output directory, cache directory, site metadata, etc. It'll be passed to the
processor function as a key on the `meta` object.

`opts` can also have an `include` property, an object containing task keys (e.g. "styles") and additional glob patterns to include for
that task. The path can be anywhere, not just local to the project - I use it to
include basic typography styles that I know I'll want in every project, but it could just as easily be used to produce a
sort-of "theme" that could be shared across multiple projects.

```javascript
opts: {
  outDir: 'dist/',
  runDir: process.cwd(),
  cacheDir: '.cache',
  clean: true,
  ignoreExisting: false,
  includeStateValues: false,
  logLevel: 'debug',
  include: { 
    styles: [{ pattern: '~/.rhedyn/styles/*.scss' }] 
  },
  site: {
    name: "My Website",
    shortName: "My Site",
    description: "A website generated from files using Rhedyn",
    author: "Your Name",
    url: "https://example.com",
    language: "en-GB",
    backgroundColor: "#ffffff",
    themeColor: "#000000"
  }
}
```

#### tasks

Tasks can be either individual task objects or arrays of task objects that run in parallel. Tasks in different array elements run sequentially, allowing you to control dependencies between task groups.

Example structure:
```javascript
tasks: [
  [
    // These tasks run in parallel
    { name: "styles", ... },
    { name: "icons", ... },
    { name: "images", ... }
  ],
  // This task runs after the above group completes
  { name: "pages", ... }
]
```

Each task object should look something like this:

```javascript
{
  name: "styles",
  inputFiles: [{ pattern: "styles/**/*.scss", ignore: "**/_*.scss" }],
  stripPaths: ["styles/"],
  outputDir: "static/styles/",
  outputFileExtension: ".css",
  processor: compileSass
}
```

**Task Properties:**
- `name`: Task identifier (required)
- `inputFiles`: Array of glob pattern objects with `pattern` and optional `ignore` properties - if set, the task will be
expanded for every file found
- `stripPaths`: Array of path prefixes to remove from input paths when generating output paths
- `outputDir`: Directory within `outDir` where processed files should be placed
- `outputFileExtension`: File extension for processed files
- `processor`: Function that processes the files (required)
- `logLevel`: optionally override the log level for a specific task
- Additional processor-specific properties (e.g., `imageSizes`, `quality` for image processing)

**Input File Patterns:**
```javascript
inputFiles: [
  { pattern: "styles/**/*.scss", ignore: "**/_*.scss" },
  { pattern: "images/*.jpg" },
  { pattern: "static/*" }
]
```

#### processors

A processor is a function that receives an object with `config` and `meta` properties and returns an object describing what was processed.

A processor that returns a `ref` will have it's `detail`, `paths`, `ref` and `fromCache` properties made available in
`meta.resources`, with the `ref` as the key under the task name:
```javascript
{
  ...meta,
  resources: {
    [task.name]: {
      [jobResult.ref]: {
        detail,
        paths,
        ref,
        fromCache
      }
    }
  }
}
```

The processor function signature:
```javascript
async function myProcessor({ config, meta }) {
  // config contains the task configuration plus file-specific properties:
  // - filePath: path to the input file being processed
  // - fileOutputPath: calculated output path
  // - fileOutputDir: directory for the output file
  
  // meta contains:
  // - opts: global configuration
  // - resources: results from previously completed tasks, structured as described above
  
  // Process the file...
  
  return {
    detail: {}, // Optional: any metadata about the processed file
    paths: [outputPath], // Array of output file paths (relative to outDir)
    deps: { // Optional: dependencies for caching
      paths: [inputFile1, inputFile2], // File dependencies
      state: [] // State dependencies (tracked automatically)
    },
    ref: "unique-identifier" // Optional: reference key for this result
  }
}
```

**Built-in Processors:**

The following processors are available from `processors`:
- `compileSass`: Compiles SCSS files to compressed CSS
- `renderMarkdownWithTemplate`: Renders markdown with Handlebars templates, includes frontmatter support
- `optimiseSvg`: Optimizes SVG files using SVGO
- `copy`: Copies files without processing
- `imageToWebP`: Converts images to WebP with multiple sizes for responsive images
- `generateFavicons`: Generates favicon sets and web app manifests

**Resources and Cross-Task References:**

Processed files are made available to subsequent tasks via `meta.resources[taskName][ref]`. For example, the image processor makes processed images available to the markdown renderer for automatic srcset generation.

Some examples can be found in `src/processors.js`, and you can find utility functions exported from this package as
`utils`. The sample processors are also exported from this module as `processors`.

## Default Tasks

The default configuration includes:

1. **Parallel processing group:**
   - `styles`: Compiles SCSS files to CSS
   - `icons`: Optimizes SVG icons
   - `images`: Converts JPG images to WebP with multiple sizes
   - `static files`: Copies static files
   - `favicons`: Generates favicon sets from source images

2. **Sequential processing:**
   - `pages`: Renders Markdown files with Handlebars templates (runs after the parallel group to access processed resources)

## Logging

Rhedyn includes comprehensive logging with configurable levels:
- `silent` (1): No output
- `error` (2): Errors only  
- `warn` (3): Warnings and errors
- `info` (4): General information (default)
- `debug`: Detailed debugging information
- `trace` (6): Maximum verbosity

Set the log level in your config:
```javascript
opts: {
  logLevel: 'debug'
}
```